The Young Woman with PKU

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A Publication of
Department of Pediatrics, Maternal PKU Study
University of Texas Medical Branch
Galveston, TX 77555-0319
Copyright (C) 1992

The purpose of this booklet is to inform you and your family of the importance of being on a low phenylalanine diet before and during pregnancy. This booklet contains:

  • An explanation of PKU
  • A description of the effect of PKU on pregnancy
  • An explanation of a research project studying the risks of PKU and pregnancy
  • A discussion of the role of your obstetrician or family doctor and the PKU treatment center
  • A list of sources for information and PKU treatment centers

The authors encourage the widespread reproduction and distribution of these materials for any educational and/or patient care related purpose and ask only that the source of the materials be acknowledged.

We hope this booklet will be a useful guide for you.


Table of Contents

Part I EXPLANATION OF PKU
What is PKU?
Are There Different Types of PKU?
What Are the Purposes of the PKU Diet?
How Long Should the Diet Be Continued?
Why Are Blood Tests and Diet Records Necessary?
How Did My Parents Know I Had PKU?
How Did I Get PKU?
Will My Children Have PKU?
What Are the Effects of PKU on Pregnancy?
What If I Decide to Have a Baby or Think I am Already Pregnant?
Summary
References
 
Part II CARE DURING PREGNANCY
Care Provided by the Obstetrician or Family Doctor and the PKU Treatment Center
The PKU Diet During Pregnancy
Weight Gain During Pregnancy
Instructions for Flavoring Medical Food
Suggestions for Eating Away from Home
NutraSweet®
Directions for Diet Record Sheets and Blood Tests
Laboratory Work Needed
Nausea
Cravings
Heartburn
Constipation
Frequency of Urination
Alcohol, Smoking and Drugs
Your Newborn Baby

Appendices:  

  1. Materials Available
  2. Low Protein Food Distributors
  3. Metabolic Centers in Texas
  4. PKU Parent Support Group and PKU Newsletters
  5. Glossary
  6. Diet Record Form


What is PKU? When your parents were informed you had PKU, their first question was, "What is PKU?". Although you have grown up with PKU, you may still be searching for an answer to this question. This booklet is designed to answer that question and to tell you about PKU and pregnancy. In order to understand PKU there are several terms that we must define. 
  1. PKU: is an inherited condition in which the body cannot properly utilize one part of protein, phenylalanine (fenel-al-ah-neen), found in foods.
  2. PKU: stands for phenylketonuria (fenel-key-ton-ur-ee-a) which means phenylketones (fenel-key-tones) in the urine.
  3. Phenylketones: are products of phenylalanine.
  4. Biochemical changes: are changes that take place within the cells of the body.

The biochemical changes related to PKU involve protein, which is necessary to support life. Protein helps to build all parts of the body. Protein is made of building blocks called amino acids (a-mee-no-acids) fastened in a chain as shown in Figure 1.

Amino acids are described as either "essential" or "non-essential." Essential amino acids are necessary for growth and must be supplied in the diet since the body cannot make them. Non-essential amino acids are also required but are made by the body. The two amino acids involved in PKU are the essential amino acid phenylalanine and the non-essential amino acid tyrosine (ti-ro-sine). In PKU, tyrosine becomes essential and must be provided in the diet.

Phenylalanine will be called PHE in this booklet and Tyrosine will be called TYR.

amino acids

Figure 1: Proteins are made of amino acids fastened in a chain. Phenylalanine (PHE) is an amino acid.

The person who does not have PKU changes phenylalanine to tyrosine. Tyrosine is used by the body to form pigments and hormones. Pigments provide skin and hair coloring while hormones, made from tyrosine, are important to the function of the brain and central nervous system. Hormones are chemicals made in the glands and released into the blood stream. Together with the nervous system, hormones coordinate and control organs so that all parts of the body work together smoothly and efficiently. Figure 2 shows the normal change as PHE becomes tyrosine in the liver. The change is due to the action of an enzyme (en-zime). Enzymes are chemical compounds that help one substance change into another. The enzyme that changes PHE to TYR is called phenylalanine hydroxylase (hi-drox-ill-ace).

In a person who does not have PKU, an enzyme in the liver changes PHE into Tyrosine. Tyrosine is used to form pigments and hormones.

Figure 2: In a person who does not have PKU, an enzyme in the liver changes PHE into Tyrosine. Tyrosine is used to form pigments and hormones.

The person with PKU has only a limited ability to change PHE into tyrosine because the enzyme does not work properly. Therefore, excess PHE builds up as shown in Figure 3. Part of the excess PHE goes into urine and part is changed into harmful products which appear in the blood and circulates to all parts of the body, including the brain, and then are lost in the urine. These harmful products in the urine are called phenylketones (fenel-key-tones) from which the condition gets the name: phenylketonuria. Since PHE is not converted to TYR in the body of the person with PKU, TYR becomes an essential amino acid and must be given in the diet.

In a person with PKU, the enzyme does not work properly causing PHE to build up.

Figure 3: In a person with PKU, the enzyme does not work properly causing PHE to build up.



Are There Different Types of PKU? There are three known types of Hyperphe: they are classified by the amount of PHE that can be measured in the blood. Blood PHE is reported by the laboratory as mg/dL (milligrams per deciliter) or mmol/L (micromoles per liter) of blood. The chart below lists the three types of Hyperphe: Mild Hyperphe, Atypical PKU and Classical PKU.

The child with Mild Hyperphe usually does not need a special diet. However, women with Mild Hyperphe should have their blood levels checked during pregnancy because they may need to be on a diet low in PHE during the pregnancy to protect the unborn baby from birth defects.

A child with Atypical PKU requires a low PHE diet during childhood. Women who are classified as Atypical PKU must be on a low PHE diet before and during pregnancy.

Persons with classical PKU should continue the low PHE diet throughout life. Women with classical PKU must be on the low PHE diet before and during pregnancy in order to have the best chance of having a healthy baby.

Standards Used by the Texas Department of State Health Services
Quantitative PHE by Fluorometric Analysis
Standards Used by the Texas Department of State Health Services
Quantitative PHE by Fluorometric Analysis
Blood Level of PHE
Diagnosis
Treatment
(mg/dL)
Micromoles/Liter
   
<4
<240
Normal None
4 - 10
240-600
Mild Hyperphe A low PHE diet is usually not prescribed during childhood.

A low PHE diet may be needed during pregnancy.

10.1 - 19.9
606-1194
Atypical PKU Requires a low PHE diet.

Women must have a low PHE diet before and during pregnancy.

20 and higher
1200 or higher
Classical PKU A low PHE diet is needed to prevent mental retardation.

Women must have a low PHE diet before and during pregnancy.



What Are the Purposes of the PKU Diet? place setting The purposes of the low PHE diet are to keep the PHE blood levels in a safe range and to give all the nutrients needed for good health. A safe blood PHE range for the nonpregnant person is less than 6 milligrams per deciliter (mg/dL) or 360 micromoles per Liter (mmol/L). Each person's dietary need for PHE is individual and depends on the activity of his/her enzyme. Therefore, the diet is personalized to meet these needs. To keep the blood PHE levels within a safe range frequent diet changes may be necessary.

A normal diet contains more PHE than is needed by the body. Non-PKU individuals have normal biochemical pathways to rid the body of this excess PHE. The PKU diet lowers the PHE intake to supply just enough PHE to build and repair body tissues and contains the tyrosine that the person with PKU cannot make. Limiting the PHE in the diet causes the blood PHE levels to drop so that harmful products (phenylketones) are not made. The PHE-restricted diet protected you from mental retardation as the harmful products are not formed.

The Medical Food used in the PKU diet is designed to:

  1. Provide a source of protein with little or no PHE
  2. Furnish vitamins and minerals
  3. Supply the tyrosine your body cannot make

High protein foods such as meat, fish, poultry, eggs, dairy products, nuts and dried beans and peas are not allowed in the PKU diet. The protein found in these foods has large amounts of PHE; therefore, the foods high in protein are high in PHE. The only foods which contain no PHE are sugar, oil, pure starch (such as cornstarch, potato starch, wheat starch) and water and products made with these ingredients.

Since PHE is an essential amino acid, measured amounts are eaten in the form of low protein foods such as fruits, vegetables and cereals. The diet is planned for each person since each individual needs different amounts of PHE. A diet that is too low in PHE may cause PHE deficiency, which would be harmful. The nutritionist helps plan a diet to give the amount of PHE needed to keep the blood PHE level in a safe range. The low PHE diet consists of the Medical Food, measured amounts of low protein foods, and free foods. Free foods are items that contain little or no PHE.

Low PHE cookbooks (Appendix A) using special products are available for making foods for PKU meals. Low protein food distributors supply special items low in PHE. The special products include low protein bread, cookies, noodles, spaghetti and wheat starch. The wheat starch is used in place of flour for baking bread, cakes, and cookies low in PHE. Appendix B contains addresses for distributors.



How Long Should the Diet Be Continued? Current research shows that the PHE-restricted diet should be continued indefinitely. In the past, some children were taken off the diet around the time they started school. A long term study of PKU children called the Collaborative Study of Children Treated for Phenylketonuria (Koch, 1982, 1984, 1985) found that children should remain on the diet longer. Many of the children taken off the diet began to lose IQ points and showed a drop in their ability to do school work. The study therefore recommended that the safer course is for children to stay on the PHE-restricted diet.

A study conducted by Dr. Dennis Shaw of the University of Washington Magnetic Resonance Imaging in PKU: Changes in Brain White Matter (Shaw, 1993) noted "we do know that high blood phenylalanine concentrations over time have a damaging effect on the structure of the brain, the findings lend support to the view that good control of blood phenylalanine should be maintained throughout life."



Why Are Blood Tests and Diet Records Necessary? Blood tests are taken on a regular basis to find the amount of PHE in the blood. There is no other way of finding out if the blood PHE level is in a safe range. Diet records are used to find how much PHE your body can tolerate and to assure that the proper nutrients are eaten. The nutritionist calculates the nutrient intake and compares the total nutrients to the daily recommendations. The diet records are essential in management of PKU. Changes to the diet cannot be made without the diet records. The nutritionist and physician at the PKU center compare the results of the blood test, nutrient intake from the diet record, and the weight before making diet changes. Instructions for filling out diet records and blood test information are listed in Part II.

How Did My Parents Know I Had PKU? PKU is usually discovered early in life. If your PKU was found early, it probably was suspected when you had a positive blood test shortly after birth. A blood test was done in the newborn nursery of the hospital by collecting blood from your heel. The test was done 24 hours (or later) after you began taking breast milk or formula. A special filter paper was used to collect the blood. The filter was checked by a Guthrie test to measure the blood PHE level. When your test was reported greater than 4 mg/dL (240 mmol/L), a second blood test was done. The results of the second test showed that your blood level of PHE was greater than 6 mg/dL (360 mmol/L) and your tyrosine was not elevated. At this point, the doctor assumed you had a form of PKU. Normal PHE levels are less than 4 mg/dL (240 mmol/L) and normal tyrosine levels are less than 3.0 mg/dL (165 mmol/L). Your physician then referred you to a PKU treatment center.

The PKU center confirmed the diagnosis by further blood and urine tests. A diagnosis of classical PKU or Atypical PKU was made by comparing the blood PHE level and the laboratory report on the urine. Classical PKU means the blood PHE level is 20 mg/dL or above and the urine has large amounts of phenylketones. Atypical PKU has blood PHE levels between 10.1 and 19.9 mg/dL (606 and 1194 mmol/L) and phenylketones in the urine.


How Did I Get PKU? Genes are responsible for your characteristics, such as eye color and height. Genes are also responsible for instructing the cells in the liver to make the enzyme that changes PHE to tyrosine. When the gene responsible for making this enzyme is altered, PKU occurs. The family tree is a simple illustration of how the altered gene was passed from your grandparents to your parents and to you.

Genes are units of inheritance found in body cells. Genes come in pairs in your cells with each parent contributing one gene to the pair in each cell. A person who has one "normal" gene and one altered PKU gene is called a carrier.

Generation I represents the possible genetic makeup of your grandparents. One of your maternal grandparents and one of your paternal grandparents are carriers of the PKU gene. One in 70 persons is a carrier of the PKU gene.

 

Generation I

Generation II represents your parents both of whom are carriers of the PKU gene. The chances of two carriers marrying are one in 5,000.

 

Generation II

Generation III represents your genetic make-up and the possible make-up of the other children in your family. For each pregnancy there is a one in four chance the child will have PKU. You inherited the PKU genes from each of your parents. PKU occurs once in 20,000 births.

 

Generation III

Your parents and grandparents probably were not aware that they were carriers of the PKU gene. This is because the carrier's "normal" gene tells the liver cells to make enough of the enzyme to break down PHE. Your parents and grandparents carry one copy of the PKU gene but do not have the disorder.



Will My Children Have PKU? The genetic make-up of your children will depend on the genes of the father of your children. These are the three genetic possibilities: 
  1. If the father of your child is not a carrier of the PKU gene, all your children will be carriers but will not have PKU.
  2. If the father of your child is a carrier of the PKU gene, for each pregnancy there is a 50% chance the child will have PKU and a 50% chance the child may be a carrier.
  3. If the father of your child has PKU, all your children will have PKU.


What Are the Effects of PKU on Pregnancy? The need for care during pregnancy was observed and reported in the 1960s and 1970s. In 1980, Drs. Lenke and Levy conducted an International Survey of women with PKU who had delivered babies. The women who were not on the diet before and during the pregnancy delivered damaged babies. The higher blood PHE levels in the mother resulted in more extensive damage to the baby.

Figure 4 represents the unborn baby of a woman with PKU who is not on the PHE restricted diet. The mother has high PHE blood levels and no source of tyrosine. As blood flows from the mother to the placenta during pregnancy, nutrients, including PHE, are transferred to the baby. The placenta concentrates some nutrients, like PHE, to help the baby grow. The blood PHE level may increase 1½ times in the baby. For example, a mother's blood level of 20 mg/dL (1200 mmol/L) may be concentrated by the placenta to 30 mg/dL (1800 mmol/L) before passing on to the baby.

Blood PHE levels that are too high place the baby at risk for birth defects, such as mental retardation, small head size, heart defects and low birth weight. The higher the mother's blood PHE level, the greater the chance that the baby will have problems. The harm to the baby is thought to be caused by the high PHE levels in the blood stream of the mother even though the mother is not obviously affected by these high PHE levels.

 

fetus

Figure 4: The mother's blood PHE is concentrated by the placenta, causing the level reaching the baby to be higher. The baby is exposed to damaging PHE levels. (Image Courtesy ALT Ultrasound)

In 1984, the Maternal PKU Collaborative Study began to study this problem. The study began collecting information on women with all types of PKU in order to understand the effects of PKU on pregnancy. The study is funded by the National Institute of Child Health and Human Development. The purpose of the study is to determine the effect of a PHE-restricted diet in preventing the birth defects associated with untreated Maternal PKU.

Figure 5 represents the unborn baby of a woman with PKU who was on diet before pregnancy and has continued to have good dietary control during pregnancy. The woman's blood PHE level is 2 mg/dL (120 mmol/L). Blood PHE levels between 2 to 6 mg/dL (120 mg/dL to 360 mmol/L) are thought to be "Safe" for pregnancy. This baby has a source of tyrosine in the Medical Food and is not exposed to damaging high blood PHE levels. The baby has a better chance to grow and develop normally.

To protect your baby, you should be on the special diet and Medical Food before you get pregnant. The diet lowers PHE blood levels and furnishes the tyrosine the baby needs for normal growth. It also supplies all the other nutrients needed by you and the baby.

 

fetus

Figure 5: The mother's PHE-restricted diet gives this baby a better chance of growing and developing normally because her blood PHE is within the range of 2-6 mg/dL (120-360 mmol/L)(Image Courtesy ALT Ultrasound)



What If I Decide to Have a Baby or Think I am Already Pregnant? Since not all pregnancies are planned, the best plan is for you to call the PKU treatment center nearest your home for information. See Appendix C for lists of centers in Texas. PKU treatment centers specialize in treating persons with PKU. The staff consists of a physician, nutritionist, and consultants such as a nurse, psychologist, and social worker. They will explain PKU and the concerns of PKU during pregnancy.

pregnant womanA schedule of tests and evaluations will be arranged for you before and during pregnancy. The staff at the PKU center will inform your obstetrician or family doctor of the recommended schedule. Care provided by the PKU center and your local doctor will give you a better chance of having a healthy baby.

The nutritionist will plan a diet for you to meet the nutritional needs for you before and during pregnancy. Remember the diet you had as a child will not be adequate for an adult or for pregnancy. If you decide to have a baby, the staff at the PKU treatment center will work with your obstetrician or family doctor during pregnancy.

If you think you may be pregnant, call AT ONCE so you will be placed on a diet to lower your blood PHE levels and provide a safe place for your baby to grow. The sooner you begin diet, the better your chances are of having a healthy baby. Cutting out high protein foods without the Medical Food does not provide an adequate diet for you and the baby. The baby needs the protein and tyrosine in the Medical Food and measured amounts of PHE from foods to grow and develop normally.



Summary
  1. PKU is an inherited condition in which the body cannot properly utilize protein found in foods.
  2. The special low PHE diet and Medical Food should be continued throughout life and especially during your childbearing years.
  3. Women with PKU who were not on diet have delivered babies with serious birth defects.
  4. Women who have remained on diet or returned to the diet before getting pregnant have delivered healthier babies.
  5. Return to the low PHE diet and Medical Food before you get pregnant, if possible, or immediately if you are already pregnant.
  6. To protect your baby during pregnancy, you should be followed by a PKU treatment center and your obstetrician or family doctor.
  7. To obtain further information, contact the nearest PKU treatment center listed in Appendix C.


References
Harmful Effects of Discontinuing Diet:
Holtzman, N., Kronman, R., van Doornik, W., Azen, C., Koch, R., "Effect of Age at Loss of Dietary Control on Intellectual Performance and Behavior of Children with Phenylketonuria," The New England Journal of Medicine Vol 314 No 10 (March 1996) 593-598.
Koch, Richard, C.G. Azen, E.G. Friedman, M.L. Williamson, "Preliminary Report on the Effects of Diet Discontinuation in PKU.: The Journal of Pediatrics Vol 100, No 6 (June, 1982) 870-875.
Koch, R., C. Azen, E.G. Friedman, M.L. Williamson, "Paired Comparison between Early Treated PKU Children and their Matched Sibling Controls on Intelligence and School Achievement Test Results at Eight Years of Age." Journal of Inherited Metabolic Disease 7 (1984) 86-90.
Koch, R., C. G. Azen, E.G. Friedman, M.L. Williamson, K. Michals, Report on the Collaborative Study of Children Treated for Phenylketonuria in R.A. Wapnir "Ed.", Congenital Metabolic Diseases Diagnosis and Treatment. New York: Marcel Dekker, Inc. (1985) 137-151.
Shaw, D.W.W., et al, "Magnetic Resonance Imaging in PKU: Changes in Brain White Matter ", Amer. J. Neurorad.:12,403406, 1991.
Maternal PKU:
Koch, R., Friedman, E., Azen, C., Hanley, W., Levy, H., Matalon, R., Rouse, B., Trefz, F., Waibren, S., Michals-Matalon, K., Acosta, P., Guttler, F., Ullrich, K., Platt, L., de la Cruz F., The International Collaborative Study of Maternal Phenylketonuria. Mental Retardation and Developmental Disabilities Research Reviews 5:117-121 1999.
Lenke, R., Levy, L. "Maternal Phenylketonuria and Hyperphenylalaninemia." New England Journal of Medicine. 303 (1202-1208). 1980.
Platt, L., Koch, R., Azen, C., Hanley, W., Levy, H., Matalon, R., Rouse, B., de la Cruz, F., Walla, C., "Maternal PKU Collaborative Study Obstetric Aspects and Outcome: The First Six Years." American Journal of Obstetrics and Gynecology. Vol 166 No 4 (April 1992) 1150-1162.
Rouse, B.M., Azen, C., Koch, R., Matalon, R., Hanley, W., de la Cruz, F., Trefz, F., Friedman, E., Shifrin, H.: Maternal Phenylketonuria Collaborative Study (MPKUCS) Offspring: Facial Anomalies, Malformations and Early Neurological Sequelae. American Journal of Medical Genetics ,Vol.69:89-95, 1997.
Waisbren, SE., Chang, P, Levy, H, Shifrin H, Allred. E., Azen C., de la Cruz F, Hanley, W, Koch R, Matalon, R, Rouse. B. Neonatal Neurological Assessment of Offspring in Maternal Phenylketonuria. J Inher Metab. Dis, Vol. 21. 21,39-48, 1998.


Care Provided by the Obstetrician or Family Doctor and the PKU Treatment Center

Your obstetrician or family doctor will provide all the routine care for your pregnancy. The PKU treatment center will provide diet management which includes monitoring your PHE blood levels. The PKU treatment center works closely with your obstetrician or family doctor throughout your pregnancy.

If you have questions regarding your diet or blood level, call the PKU treatment center. Other questions will be handled by your obstetrician or family doctor. Copies of correspondence to you from the PKU center will be sent to your obstetrician or family doctor in order that your medical records may be kept current.



The PKU Diet During Pregnancy There are two purposes of the diet during pregnancy. One purpose is to provide the nutrients needed by you and your baby. The other purpose is to keep the blood PHE level within a "safe" range, which is thought to be between 2 to 6 mg/dL (120 TO 360 mmol/L). The main source of protein, vitamins and minerals will be your Medical Food. The PKU staff will help you choose the best Medical Food for you and the nutritionist will plan your diet.

The Medical Food provides most of your protein, including tyrosine, which are increased during pregnancy, but without excess PHE. The necessary amount of PHE will be provided by the foods allowed in your diet.

Supplements to the diet will be prescribed by the nutritionist, if needed, to make your diet complete for you and your baby throughout pregnancy. Do not take regular prenatal vitamins and minerals because too much can be harmful. Take only the supplements prescribed by the nutritionist.

Your diet will be changed according to your blood PHE level, other laboratory reports and weight gain pattern. The low PHE diet consists of a Medical Food, diet supplements, measured amounts of low protein foods (to supply the PHE needed) and free foods. The free foods contain little or no PHE and are used to help meet your calorie needs. The nutritionist will give you an outline of your daily diet guide and lists of low protein foods divided into groups. During the last period of the pregnancy, some women require larger amounts of PHE to keep the blood level in the desired range. If this occurs, you may be given measured amounts of high protein.

Be sure to drink at least 6 to 8 glasses of liquids each day including your Medical Food, prescribed juice and water. The fluids help your kidneys get rid of waste products, prevent constipation and aid digestion.



Weight Gain During Pregnancy A gradual weight gain during pregnancy is recommended. You gain weight as your baby grows and your body changes to meet your baby's needs. During the first 3 month period (1st trimester), your baby is beginning to develop; during the second 3 month period (2nd trimester) the baby continues to grow and your body weight increases more rapidly. The last 3 month period (3rd trimester) your baby has rapid growth.

The pattern of weight gain is important. You should gain weight rapidly in the last 6 months of your pregnancy (2nd and 3rd trimesters). If you are average size and body build and have always weighed the desirable weight for your height, you should gain between 25 and 35 pounds during your pregnancy. If you were underweight when you became pregnant, you should try to gain between 28 to 40 pounds throughout your pregnancy in order to nourish and protect your growing baby. If you were overweight when you became pregnant, you should still gain between 15 to 25 pounds. If you are pregnant with twins, you should gain between 35-45 pounds.

Never try to lose weight when you are pregnant. Even if you have gained a lot of weight early in your pregnancy, you should eat an adequate diet to continue to gain gradually. Adequate nutrition during pregnancy is necessary because of the baby's rapid growth and also for the storage of nutrients.


Instructions for Flavoring Medical Food

  1. Use caffeine-free carbonated beverages instead of water to mix Medical Food.
  2. Add extracts (vanilla, almond, mint).
  3. Add chocolate syrup or Chocolate Quik®.
  4. Mix Medical Food with some of the fruit or fruit juice allowance. Fruit will puree in the blender as the formula is mixing.
  5. Freeze flavored Medical Food into "popsicles" or "slush."
  6. Mix enough water or fruit juice with dry Medical Food to make a paste of pudding-like consistency. Add sugar and spices.
  7. Mix dry powder with Mocha Mix Non-Dairy Frozen Dessert®.
  8. Prepare pudding (banana cream, butterscotch, lemon, tapioca, vanilla) with a non-dairy product (such as Rich's Richwhip Topping®), then add dry Medical Food powder to mixture.
  9. Add dry powder to Sorbet® by Dole Company.

Use PHE food lists for PHE content of these flavorings.



Suggestions for Eating Away from Home Beverages: Your Medical Food (prepared at home in an airtight container), apple juice, cranberry juice, orange juice, pineapple juice, tea, lemonade, Hi C Drink®, Tang®, Kool-Aid® (without NutraSweet®), or carbonated beverages (without NutraSweet®).

Sandwiches: Order low protein breads or wheat starch to make your own low protein bread (Appendix B). Sandwich fillings may include mushrooms, bean sprouts and avocado; shredded carrots, black olives and mayonnaise; coleslaw; sliced cucumbers and tomatoes; diced celery, raisins, lemon juice and mayonnaise; banana and mayonnaise; pineapple and mayonnaise; lettuce, tomatoes, onion and pickle relish.

Soups: vegetarian vegetable, Cup-of-Soup®, and homemade soup.

Salads: vegetable salad, fruit salad, and low-PHE pasta salads.

Desserts: fresh fruits; low PHE cookies, cupcakes, or cakes from the special cookbooks; gum drops, hard candy, and jelly beans; Hunts Lemon Pudding Snack Pack®; Comstock Pie Fillings® and dried fruit snacks.

Treats: Fruit Roll Ups®, low protein rusk with jelly, Pepperidge Farm Goldfish Crackers®, dried apricots, dried banana chips, potato chips, Weight Watcher's Fruit Snacks®, pickles, and olives.

Contact your nutritionist for further assistance in menu planning for meals eaten away from home.



NutraSweet® Products containing NutraSweet® (also called Equal®) should not be used. NutraSweet®, a low-calorie sweetener, is made of aspartame which is 56% phenylalanine. To avoid eating products with NutraSweet® read all labels. Aspartame is listed in the ingredients, and the statement PHENYLKETONURICS: CONTAINS PHENYLALANINE is printed on the label.

NutraSweet® is used in many items, including low-calorie soft drinks, dry mixes for beverages such as Kool-Aid®, desserts, cereals and chewing gum. NutraSweet® is also used in many medications. The warning statement is not required on the medications therefore you must read the labels and look for the word aspartame. Ask your nutritionist for a listing of foods and medicines containing NutraSweet® (aspartame). The hot line number for NutraSweet® information is 1-800-321-7254.



Directions for Diet Record Sheets and Blood Tests Write down all the foods and beverages eaten for 3 days before the blood test. For example, if the blood is to be drawn on Thursday at 1:00 P.M., the diet records should be kept for Monday, Tuesday, Wednesday, and up until 1:00 P.M. on Thursday. See sample diet record sheet Appendix F.

At the top of the form, fill in your name: birthdate; height, and weight (and where you were weighed).

Write down how you mixed your Medical Food: List ingredients, amounts and the total volume of the mixture and changes in ingredients from day to day.

Record vitamins and minerals, if taken, with brand names and number of tablets taken each day.

Answer questions in the health section. Illness may increase your blood PHE level. Fill in date blood is drawn and the time of your last meal.

On diet diary pages write the date and time foods or liquids are taken and the amount you ate. Include the Medical Food taken each day. Use gram scales, standard measuring cups, spoons and a small ruler to measure the foods and liquids. Write liquids in ounces and solids in tablespoons, cups, grams, or units, such as 1 small apple.

Measure dry cereal from the box; and cooked cereal after cooking. Measure cooked vegetables after cooking. List brand names on items eaten.

Record food intake in a notebook at home before mailing the sheets. If the diet sheets are lost in the mail, the nutritionist will call you for the food record.

Mail your diet record to your nutritionist the day you have your blood test. This allows the nutritionist to calculate the diet and record the weight gain by the time the blood PHE level is reported by the laboratory. Decisions for your diet management are based on your diet intake, weight gain and blood PHE level. Changes cannot be made based on the blood test alone. Diet records are important for your care.

The blood is drawn at the office of your obstetrician or family doctor, Public Health Clinic, or you may collect the blood at home. It should be mailed first class to the laboratory. The blood PHE is measured and the results are sent to the PKU treatment center and to your obstetrician or family doctor.

After the PKU staff has evaluated the diet records, weight gain and blood PHE level, you will be given the results, and the diet changes, if needed, and will be informed as to the date of the next blood test. A follow-up letter stating the blood level and necessary diet changes is sent to you and to your obstetrician or family doctor.



Laboratory Work Needed In addition to your routine laboratory work needed for pregnancy, you will need blood tests to check your nutritional status. The results of these tests are used in making changes in the mineral, vitamin and protein content of your diet as well as the PHE content.

An ultrasound will be done about four times during your pregnancy to determine how the baby is developing. Ultrasound is a device that sends sound waves through body tissues. It records the echoes as the sounds find the baby and changes the recording into a picture. The pictures are used to measure the size and shape of the baby.


Nausea Some women feel queasy or nauseated during pregnancy. The following suggestions may help:

  1. Before rising - eat some dry cereal, saltine crackers or low protein crackers. Keep these foods at your bedside. After you eat, keep your head on the pillow, then wait 15 minutes before getting up.
  2. Meals - keep your meals small and eat very often. Eat hourly if needed. Avoid long periods without food. An empty stomach secretes acid that can make the nausea worse.
  3. Fluids - drink your fluids between, rather than with meals, except for your Medical Food, which you should take while eating.
  4. Fats - avoid greasy foods.
  5. Spices - eat only lightly seasoned foods.
  6. Fruits and vegetables - eat tomatoes, grapefruit, apple or other fruits and vegetables.
  7. Cooking - try to eat something to pacify your stomach before you begin cooking. If you are feeling queasy, fix cold foods, since they have less odor.
  8. Avoid - strong unpleasant smells such as street fumes and cigar smoke.


Cravings Some pregnant women find they have a strong desire to eat non-foods, such as clay or laundry starch. If you have this kind of craving, do not eat these non-food items. Discuss this with your nutritionist so food items can be substituted. Eating clay or starch interferes with the digestion of the foods you need for your baby to grow properly.

Some pregnant women find they have a strong desire to eat non-foods, such as clay or laundry starch. If you have this kind of craving, do not eat these non-food items. Discuss this with your nutritionist so food items can be substituted. Eating clay or starch interferes with the digestion of the foods you need for your baby to grow properly.

Some pregnant women find they have a strong desire to eat non-foods, such as clay or laundry starch. If you have this kind of craving, do not eat these non-food items. Discuss this with your nutritionist so food items can be substituted. Eating clay or starch interferes with the digestion of the foods you need for your baby to grow properly.

Some pregnant women find they have a strong desire to eat non-foods, such as clay or laundry starch. If you have this kind of craving, do not eat these non-food items. Discuss this with your nutritionist so food items can be substituted. Eating clay or starch interferes with the digestion of the foods you need for your baby to grow properly.

   Some pregnant women find they have a strong desire to eat non-foods, such as clay or laundry starch. If you have this kind of craving, do not eat these non-food items. Discuss this with your nutritionist so food items can be substituted. Eating clay or starch interferes with the digestion of the foods you need for your baby to grow properly.

 Some women feel queasy or nauseated during pregnancy. The following suggestions may help: 

Some pregnant women find they have a strong desire to eat non-foods, such as clay or laundry starch. If you have this kind of craving, do not eat these non-food items. Discuss this with your nutritionist so food items can be substituted. Eating clay or starch interferes with the digestion of the foods you need for your baby to grow properly.


Heartburn Heartburn is a burning pain in the area of your heart, sometimes felt after eating. It has nothing to do with your heart. You may feel as if you have indigestion and have to burp a lot. Heartburn sometimes causes an unpleasant taste in the mouth.

This feeling is due to the fact that your body hormones change during pregnancy. The hormone changes cause the muscles that control the opening between your stomach and esophagus to relax. As the muscles relax, the stomach acids move into the esophagus causing discomfort. Late in pregnancy the increasing size of the baby pressing on the stomach may make the heartburn more noticeable.

These tips may help relieve the discomfort of heartburn: Eat slowly, chew your food well, eat small meals more often, avoid spicy, greasy foods. Do not lie down after eating - either sit straight up or walk. Also do not bend over, stoop or pick up things for about 30 minutes after eating. Sleep with extra pillows to elevate your head and torso.


Constipation Pregnant women sometimes become constipated particularly toward the end of the pregnancy. Constipation means hard stools which are difficult to pass. It is not related to how often the bowels move. The hormone changes during pregnancy cause the smooth muscle in your intestines to relax and this causes constipation. The following suggestions may be helpful should this occur: 

  1. Increase fluids in the diet by drinking more water, juice, or eating foods high in water such as fruits, vegetables or popsicles.
  2. Increase fiber in the diet. The bulk in fiber can help keep stools soft as well as helping them move down the intestinal track. Fiber can be added by eating fruits such as dried or steamed prunes, apricots or raisins; fresh fruits with the skins such as apples, plums, peaches, pears; and vegetables. Serve fruits and vegetables raw or lightly steamed. Do not cook until mushy. Kellogg's Bran Buds® may be added to cereal or fruits (1 Tablespoon = 24 mg PHE).
  3. Exercise daily. Long trips and inactivity can promote constipation. Try to stop and walk around during long trips in the car.
  4. Form daily bowel habits. A warm drink just before your regular toileting may help the process.

If these suggestions do not relieve your constipation, inform your obstetrician or family doctor.



Frequency of Urination Frequency of urination means that you have to go to the bathroom a lot. This often happens early and late in pregnancy. As the baby grows there is less room for your bladder to hold urine. DO NOT cut down on the amount of fluids you drink because you think you will have to go to the bathroom less often. Continue drinking plenty of fluids and put up with this inconvenience. Adequate fluids are important throughout pregnancy. Extra water helps the kidneys handle the concentrated protein in your Medical Food.

Alcohol, Smoking and Drugs A pregnant woman who drinks alcoholic beverages risks having a child with birth defects. Babies born to women who drank alcohol during pregnancy have had heart defects, malformed facial features and low birth weight. Most scientists believe that alcohol in pregnancy causes mental retardation. When you drink, your baby drinks. Since nobody knows how much is too much, most doctors feel it is wisest not to drink any form of alcohol at all during pregnancy.

Women who smoke tend to have low-birth weight babies. Newborns who weigh 5½ pounds or less at birth are more likely to develop health problems than babies who weigh closer to 7½ pounds. Smoking also increases the possibility of having a miscarriage and pregnancy complications. Mothers who stop smoking may spare their babies possible damage.

You should take only medications prescribed by your doctor. Don't take any other drugs, including street drugs and drugs bought over the counter without a prescription.



Your newborn will be tested for PKU just as you were tested when you were born. The baby will need a special diet only if he/she has PKU. You may breastfeed your baby. Your nutritionist will give you further advice for feeding your child. The PKU team will follow your baby's growth and development carefully and inform you of his/her progress.

Appendix A
Materials Available
  1. BOOKLETS:
    1. Maternal Hyperphenylalaninemia, (1984, 6 pages: single copy free). Booklet written for young women with PKU or hyperphenylalaninemia, their families and friends. (Also available in Spanish)
      Source: PKU Clinic Linda Tonyes
      St. Christopher's Hospital for Children
      Section of Neurology
      Erie Ave at Front St.
      Philadelphia, PA 19134
      215 427 5493
    2. PKU and Teens: Planning Makes it Easier, (1987, 29 pages: single copy free). Designed to help teenagers with PKU learn more about PKU, its treatment, and application of dietary treatment needs to situations usually encountered by teenagers.
      Source: Illinois Dept. of Public Health, Div. of Family Health
      Genetic Diseases Program
      535 W. Jefferson St.
      Springfield, IL 62761
    3. Monitoring Blood Levels at Home: For Infants, Children and Adults, with PKU and other Disorders, 1992, $1.00. Shows how to obtain blood samples using the Penlet and Guthrie card system.
      Source: Dr. Richard Allen
      Pediatric Neurology
      Metabolic Disease Clinic
      Box 0202/L3222 Women's Hospital
      University of Michigan Medical Center
      1500 East Medical Center Drive
      Ann Arbor, MI 48109-0202
      (734) 763-4697
    4. Women with PKU, (1997), 18 pages; PKU, Pregnancy and You (1987) 24 pages. Single copy free Booklets written for young women with PKU, answering common questions about PKU and Maternal PKU. A list of all PKU clinics in California.
      Source: California Dept. of Health Services, Newborn Screening Program
      2151 Berkeley Way, Annex 4
      Berkeley, CA 94704
      (510) 540-2534
    5. Cristine M Trahms, MS,RD,FADA
      PKU/Biochemical Clinic, Box 357920
      University of Washington
      Seattle, WA 98195

      Educational materials for persons with PKU (children and adults)
      The University of Washington PKU Clinic web site:
      http://depts.washington.edu/pku/

    6. Materials for Maternal PKU developed with support of the Pacific Northwest Regional Genetics Group PacNoRGG) accessed from http://depts.washington.edu/pku/ and PacNoRGG web site: http://mchneighborhood.ichp.edu/pacnorgg/
  2. VIDEOS:
    1. Hidden from View: PKU in the Teen,(1985), 12 minutes VHS videotape ($10.00) + 20 page booklet, make check to Univ. Michigan, account U002431, A booklet and video for adolescents who are off diet explaining PKU and the importance of returning to diet.
      Source: Pediatric Neurology Metabolic Clinic
      Box 0202/L3222 Women's Hospital
      University of Michigan Medical Center
      1500 East Medical Center Drive
      Ann Arbor, MI 48109-0202
      (734) 763-4697
  3. LOW PROTEIN FOOD LISTS AND COOKBOOKS:
    1. Low Protein Food List for PKU, (1995) $35.00 - US residents, $37.00 in US funds for Canadians. Foreign $40 US funds, Washington state residents only, add $3.01 tax per book. Pay by check or Money Order (draw on US funds only) Make checks payable to Dietary Specialties, Inc. MasterCard and Visa accepted, send Exp. Date and signature.
      Source: Dietary Specialties, Inc.
      P.O. Box 227
      Rochester, NY 14601
      1-800-544-0099
    2. Low Protein Bread Machine Baking for PKU, $15.00 US residents, $18 US funds Canadians, Foreign $21 US funds Washington State residents only add $1.29 tax per book. Make checks to Dietary Specialties. MasterCard and Visa accepted, send Exp. Date and signature.
      Source: Dietary Specialties, Inc.
      P.O. Box 227
      Rochester, NY 14601
      1-800-544-0099
    3. Low Protein Cookery for PKU, 3rd edition, $21.95 US plus $3.50 shipping for first book, each additional book add $0.75. Tax for IL add $1.92, Canadians add GST $1.53 US funds. Pay by check or Money Order drawn on US funds only. Outside US add shipping for first book add $4.50 US funds, each additional add $1.00 US funds. Make check to Chicago Distribution Center. MasterCard, Visa accepted, send Card # and Exp. Date plus signature. Recipes appropriate for management of PKU. Includes PHE values per serving.
      Source: Chicago Distribution Center
      11030 S. Langley Ave.
      Chicago, IL 60628
      1-800-621-2736


Appendix B
Low Protein Food Distributors
  1. Dietary Specialties
    10 Leslie Court
    Whippany, NJ 07981
    Tel: 1-888-640-2800
    www.dietspec.com
  2. Ener-G Foods
    5960 1st Ave. S.
    P.O. Box 24723 84488
    Seattle, WA 98124
    Tel. 1-800-331-5222
  3. Med-Diet, Inc.
    3600 Holly Lane Suite 80
    Plymouth, MN 55447
    Tel. 1-800-633-3438
  4. Scientific Hospital Supplies of North America
    Low Protein Foods (Loprofin Products)
    P.O. Box 117
    Gaithersburg, MD 20884
    Tel: 888-LOPROGO (888-566-7646)

Appendix C


Appendix D
PKU Support Groups and PKU Newsletters

  1. National PKU News
    One year subscription $18.00 for US residents, $22 US funds for Canada, $28 US funds for foreign
    Virginia Schuett, MS, RD
    6869 Woodlawn Ave. NE #116
    Seattle, WA 98115
    Web site: http://www.pkunews.org
  2. Arizona - Metabolic Messages Newsletter
    Office of Nutrition Services
    Arizona Department of Health Services
    1740 West Adams, Room 208
    Phoenix, Arizona 85007
    (602) 542-2831
  3. California - Children's PKU Network
    3790 Via de la Valle Suite 116E
    Del Mar, CA 92014
    858-509-0767 Toll-Free: 800-377-6677
    FAX 858 509 0768
    pkunetwork@aol.com
  4. Colorado - PATHWAYS Newsletter
    University of Colorado Health Science Center
    The Children's Hospital
    Inherited Metabolic Diseases Clinic
    1056 East 19th Ave. Box 153
    Denver, CO 80218
    (303) 861-6847
    1-800- 624-6553 ext.6847
  5. Illinois - PKU Press Newsletter
    PKU PRESS Editor
    P.O. Box 102
    Palatine, IL 60078-0102
    PKU organization of IL voice mail (630) 415-2219
    Info@pkuil.org to contact the editor Web site: http://www.PKUIL.org
  6. Michigan - Association for Neuro-Metabolic Disorders Newsletter
    Pediatric Neurology Metabolic Clinic
    Box 0202/L3222 Women's Hospital
    University of Michigan Medical Center
    1500 East Medical Center Drive
    Ann Arbor, MI 48109-0202
    (734) 763-4697
  7. Texas - PKU Connections
    The newsletter can be viewed from http://www.dshs.state.tx.us/newborn/pku.shtm

    Gulf Coast PKU Association
    Support group for Gulf Coast Area (Houston, Galveston, Austin)

    Contacts:
    Cindy Kirsch
    21711 Slippery Creek Lane
    Spring, Texas 77388
    ckirsch@ev1.net

    Cathi Perkins
    2910 Wyoming
    Dickinson, Texas 77539
    281-336-2301
    cperkins@spacenter.com

    Cathleen Connolly, RD, LD
    Hermann Children's Hospital
    713-704-2120
    cathleen_connolly@mhhs.org

  8. http://depts.washington.edu/pku/ University of Washington PKU Clinic - This site was developed by the University of Washington PKU clinic team, including a parent advisory group and clinic staff, to provide resources to families of children with PKU and professionals who work with children with PKU.
  9. On line PKU Internet group
    Administrator: Linda Gilbert (parent).
    To Subscribe, send an email to macpku@aol.com, requesting to be added to the mailing list with the following information: First name: Last name. Email address.

Appendix E
Glossary

Amino Acids: Units which combine to form proteins.

Carrier: A person who has an altered PKU gene which may be passed on to children. This person does not have PKU.

Chromosome: A structure found in every cell which carries the genes.

Deciliter (dL): A metric measure of volume equal to 1/10 liter (approximately 3-1/3 fluid oz).

Enzyme: A chemical compound which helps one substance change into another. An enzyme helps PHE to change to tyrosine.

Essential Amino Acid: An amino acid which cannot be made by the body and must be provided in the diet.

Gene: Units of inheritance found in body cells.

Genetics: The branch of biology dealing with the process by which traits are passed from parents to children.

Guthrie Test: A blood test for newborns that measures PHE level.

Inherit: To receive from one's parents and other ancestors by genetic transmission.

Maternal PKU: A term used when referring to a pregnant woman who has PKU.

Micromoles (mmol): A unit of measure used to express PHE concentration in blood.

Non-essential Amino Acid: An amino acid which can be made in the body if the enzyme system is working correctly.

NutraSweet®: A sugar substitute made of aspartame which contains 56% phenylalanine. This product should not be used by persons with PKU.

Phenylalanine (PHE): An essential amino acid which accumulates in PKU women off diet and damages unborn infants.

Phenylalanine Hydroxylase: The enzyme which changes phenylalanine into tyrosine. The enzyme does not work properly in persons with PKU.

Phenylketone: A breakdown product of PHE found in excessive amounts in the urine of untreated PKU persons.

Phenylketonuria (PKU): An inherited disorder in which the body cannot change PHE to tyrosine. The buildup of PHE in the blood can cause birth defects in infants born to women with PKU who are not on the PHE restricted diet.

Protein: Compounds made of amino acids that are essential for all living cells of the body.

Tyrosine: A non-essential amino acid which is made of PHE in the non PKU person. It becomes an essential amino acid in the person with PKU and must be supplied by the diet.



Appendix F
Diet Record Form
The Diet Record Form is also available in PDF. (PDF file 8K).

Name
_____________________________________________________________________

Birthdate: _____/_____/_____ Height: _____ Feet _____ Inches or _____ Centimeters

Weight: __________Pounds or _____ Kilograms
Where Weighed _____ Home _____Doctor's Office _____ Other Specify __________

Write down how you mix your Medical Food (Formula):


INGREDIENT         AMOUNT
________________________________________________
________________________________________________
________________________________________________
TOTAL VOLUME ___________________________________

Did the ingredients and/or amounts change from day to day? Yes _____ No _____
If yes, indicate the changes.
________________________________________________
________________________________________________
________________________________________________
________________________________________________

Do you take any vitamin or mineral supplements? Yes _____ No _____
If yes: List brand name of each tablet                        Number of tablets taken

_______________________________________    Day 1   Day 2   Day 3
_______________________________________    _____   _____   _____
_______________________________________    _____   _____   _____
_______________________________________    _____   _____   _____

Were you ill during the time of the diet record? Yes _____ No _____

 

If yes: Did you have a fever? Yes _____ No _____
Did you vomit? Yes _____ No _____
Did you have diarrhea? Yes _____ No _____

Comments: __________________________________________________

Blood Drawn: (Date) _____/_____/_____ (Time) _____ (Time of last meal) _____ AM/PM

Last Day of Diet Record: _____/_____/_____    Gestational age: _____weeks

Diet Diary

On the following forms, write down everthing you eat and drink. Make sure you write down the date and include the Medical Food. Write one food or drink per line and skip a line between days.

Diet Diary
Date
Time
Foods & Liquids Taken
Amount
PHE
PRO
Kcal
             
             
             
             
             
             
             
             
             
             
             
             
             
             
             
             
             
             
             
             
             
             
             

 


Written by, consultants and edited by.
Written by:
Lois Castiglioni, M.S., R.D., L.D.
Nutritionist

Bobbye M. Rouse, M.D.
Professor, Pediatrics

  Consultants:
Phyllis B. Acosta, Dr. P.H.
Kimberlee Michals-Matalon, Ph.D., R.D.
Frances Rohr, M.S., R.D.
Elizabeth Wenz, M.S., R.D.




Edited by:
Cathleen Connolly, R.D., L.D.







This booklet was made available for use in the Maternal PKU Collaborative Study and funded in part by the National Institute of Child Health and Human Development (contract #NO-1-HD-2-3156).

N.I.H. Project Officer: Felix de la Cruz, M.D. Contracting Officer: Harvey Shifrin 


Please Note: External links to other sites are intended to be informational and do not have the endorsement of the Texas Department of State Health Services. These sites may also not be accessible to persons with disabilities.

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Last updated December 07, 2010